Ideas for week long tramp with easy transport?

One last chime from me: Be sure to check out DOC's NLNP Visitor Centre in St. Arnaud before embarking on your adventure. The staff are friendly and knowledgeable, and can verify or otherwise refine the weather forecast posted just outside the VC. They can also advise of park conditions regarding tracks and facilities. It also has cool displays about the park's history, pest control programs, flora, and fauna, which includes a model of a sandfly enlarged to nearly human-sized, with whom, if not already, you will become acquainted while visiting the park. Although the general store in St. A is very friendly and has an impressive food/supply selection for its size and location, best to supply beforehand in a larger town such as Nelson unless you can afford to take out a second mortgage. Regarding transpo', hitching is always a great option in NZ: reported from mates to be safe for women; personal experience of pretty easy most times and a great way to meet the locals. Check out @Dodgydave's suggestion of dialling up www.nelsonlakesshuttles.co.nz and scope their budget fares link to get a good deal from Picton, Nelson, even Kawatiri Junction if on Intercity to St. A. Also on their website are some great trip reports from the areas you may be considering. In Lewis Pass, www.eastwestcoaches.co.nz runs a daily return service between Westport and Christchurch. May coincide with a St. A to Lewis Pass run.